Constant mesh starter



Feb. 8, 1969 J, E MaoAFEE ETAL 3,428,034

CONSTANT MESH STARTER Filed Jan. 17, 1967 E- E.. INVENTORS "gmac,

J. E, MaCAr-'EE y ETAL CONSTANT MESH STARTER Fe. 18, 1969 y Filed Jan. 1,7, 1967 INVEN'TO m7277763 5.4 aZer? Feb. 18, 1969 1 E MaGAFEE ETAL 3,428,034l

CONSTANT MESH STARTER Filed Jan. l?, 1967 sheet -3 ors United States Patent O 3,428,034 CONSTANT MESH STARTER James E. MacAfee, Troy, Robert L. Davis, Birmingham,

and Gerald P. Hentschel, St. Clair Shores, Mich., as-

signors to Chrysler Corporation, Highland Park, Mich.,

a corporation of Delaware Filed `lan. 17, 1967, Ser. No. 609,891

U.S. Cl. 123-179 Int. Cl. F02n 11/00;F01l1/00;G05g3/.00

7 Claims ABSTRACT F THE DISCLOSURE Snmmary of the invention It is an object of the present invention to provide an improved starter mechanism for a motor vehicle. A more specific object is to provide an improved motor vehicle starter mechanism of the constant mesh type.

The starter mechanism of the invention is designed for use with a motor vehicle engine of the type including a crankshaft. The starter mechanism comprises a ring gear mounted concentrically around the engine crankshaft and connected to the crankshaft by an overrunning clutch, and a pinion gear secured to the output shaft of an electric motor and maintained in constant meshing engagement with the ring gear. IIn the disclosed embodiment of the invention, the ring gear is mounted forwardly of the engine block on a forward extension of the crankshaft with the output shaft of the electric starter motor positioned at right angles to the crankshaft axis to establish a constant mesh, right angle gear connection between the ring gear and the pinion.

According to a further feature of the invention, a casing surrounds the ring gear and a spring is positioned between the casing and the side of the ring gear opposite the ring gear teeth to bias a bearing surface defined on the toothed side of the ring gear against a bearing surface defined on the casing.

Brief description of drawings A preferred embodiment of the present invention is shown in the accompanying drawings wherein:

FIG. 1 is a schematic view of a motor vehicle ernbodying a starter mechanism according to the invention;

IFIG, 2 is a longitudinal cross-sectional view of the starter mechanism of the invention;

FIG. 3 is a fragmentary cross-sectional IView of the starter mechanism of FIG. 2 taken on line 3-3 of FIG. 2, FIG. 2 in turn being taken on line 2-2 of FIG. 3;

FIG. 4 is a fragmentary cross-sectional view taken on line 4-4 of FIG. 2; and

FIG. 5 is a fragmentary cross-sectional View taken on line 5 5 of FIG. 3.

Detailed description of the preferred embodiment The starter mechanism of the invention is adapted for use with a motor vehicle of the type seen schematically in FIG. 1 and including front wheels 10, an internal combustion engine 11, transmission 12, drive shaft 14, differential 187 rear axles 20, and rear wheels 22. The starter mechanism of the invention, identied generally 3,428,034 Patented Feb. V18, 1969 ice at 23, is shown schematically in FIG. 1 and in detail in lFIGS. 2-5.

As best seen in FIG. 2, starter mechanism 23 is secured to the forward wall 24 of the block 26 of internal combustion engine 11. Internal combustion engine 11 has a crankshaft 28 journaled in block 26 and projecting at the rear of the block for connection in known manner to transmission 12. Crankshaft 28 projects at its forward end through forward wall 24 of block 26 to provide a forward crankshaft extension 28a. A timing sprocket 30 and a hub 32 are press fitted on crankshaft extension 28a and maintained in axial alignment by a common key y34. A ring gear 36V extends concentrically around hub 32 and is connected to hub 32 by an overrunning or one-way clutch C, best seen in FIG. 4.

Overrunning clutch C is provided by a plurality of pockets 38 defined by cut-outs at the inner periphery of ring gear 36 and a roller 40 in each of pockets 38 rollably engaging the outer periphery 32a of hub 32 and the radially outer wall 38a of the pocket. Outer wall 38a of each pocket tapers outwardly away from an arc centered on the central axis of hub 32 so that the rollers 40 bind up between hub 32 and ring gear 36 in response to counterclockwise (as viewed in FIG. 4) rotation of ring gear 36 relative to hub 32, While freely permitting overrunning or counterclockwise movement of hub 32 relative to ring gear 36, Springs 42 in pockets 38 act to maintain rollers 40 in rolling contact with the outer periphery of hub 32 and the radially outer wall 38a of the respective pocket. The inner peripheral portions 36a of ring gear 36 between pockets 38 provide bearing surfaces which function to journal the ring gear on hub 32. Gear teeth 43 are formed at the outer periphery of ring gear 36 in the left side face of that gear, as viewed in FIG. 2. Gear teeth 43 are of the screw type. Ring gear 36 may comprise, for example, a Spiroid gear as supplied by Spiroid Division of Illinois Tool Works, Chicago, Ill.

Sprocket 30, hub 32 and ring gear 36 are enclosed in a casing 44 suitably secured to the forward end wall of block 26. Casing 44 includes an arcuate bottom wall portion 44a, a conical annular flange portion 44b locally thickened at circumferentially spaced locations 44C to provide threaded bolt holes 44d, a chain housing portion 44e formed as an upward extension of arcuate bottom wall portion 44a and covering a timing chain 46 driven at its lower end by crankshaft timing sprocket 30 and driving at its upper end a camshaft timing sprocket (not shown), and a trough portion 44f angled rearwardly and upwardly from ange portion 44b and passing between the two strands of timing chain 46.

A stamped cover 48 is clamped to the forward end of casing 44 by a plurality of circumferentially spaced bolts 49 threaded into bolt holes 44d in locally thickened portions 44e of the casing. Cover 48 includes a central hub portion 48a terminating in a downturned flange 44b defining a central opening 44e passing the forward end of hub 32. An elastomer sealing ring 50 is clamped against flange 44b by an angle member 52; ring 50 sealingly engages the periphery of hub 32.

A bolt 54 threaded into a tapped bore 56 in the free end of crankshaft extension 28a coacts with a washer 57 to assist in locating the various parts of the starter mechanism during assembly operations.

An annular spring member 58 is positioned between an annular surface 36a defined on the right hand face of ring member 36 (as Viewed in FIG. 2) and a reaction surface 48d defined by an annular wall portion of cover 48. Spring member 58, as best seen in FIGS. 3 and 5, comprises a central flat ring portion 58a and a plurality of spring finger portions 58b joined to ring portion 58a by neck portions 58C. In assembled relation, spring fingers 58b press resiliently against cover surface 48d to press neck portions 58C against annular surface 36a and thereby press an annular bearing surface 36d on the gear tooth side of ring member 36 against an annular bearing surface 44g defined by casing 44. Ring portion 58a of spring member 58 acts as a retainer to prevent axial displacement of rollers 40 out of pockets 38.

Referring now to FIG. 3, casing 44 includes a bracket portion 44h formed as a lateral extension of the main body portion of the casing. Casing portion 44h includes thickened portions 44i defining threaded bores 44j. An electric starter motor 60 of known form is secured to casing portion 44h by bolts 62 threaded into threaded bores 44k. The output shaft 64 (FIG. 4) of motor 60 extends at right angles to the axis of crankshaft 28 and passes at its free end through a suitable opening in the casing 44 to dispose a screw type pinion gear 66 carried on the free end of the output shaft in meshing engagement with the gear teeth 43 on ring gear 36. Pinion 66 may comprise, for example, a Spiroid pinion as supplied by Spiroid Division of Illinois Tool Works of Chicago, Ill. Casing 44 is locally deformed at 44k to accommodate pinion 66.

A multi-sheave pulley 68 is clamped to the forward end of hub 32 by a plurality of bolts 70 threaded into suitable bores in hub 32. Pulley 68 includes a hub portion 68a and a sheave portion 68b defining a plurality of sheaves each receiving a separate accessory drive belt 70. An inertia ring 72 is carried on the hub portion 68a of pulley 68 with an elastomer ring member 74 positioned concentrically between hub portion 68a and inertia ring 72.

Pinion gear 66 and ring gear 36 remain in constant meshing relationship. When it is desired to start internal combustion engine 11, motor 60 is energized to rotate output shaft 64 and thereby pinion gear 66. Pinion gear 66 in turn drives ring gear 36 with a screwing action and ring gear 36 drives hub 32a through locked up rollers 40 of overrunning clutch C. As soon as the engine is running under its own power, starter motor 60 is de-encrgized and hub 32 overruns ring gear 36 through the now freely rotating rollers 40.

During the starting or screwing action of pinion 66 on ring gear 36 a relatively large axial force is developed tending to separate pinion 66 and ring gear 36 by moving ring gear 36 axially forwardly relative to hub 32. This axial separating force need not be taken by spring member S8, however, since rollers 40 lock up in pockets 38 as soon as the starting action is commenced to generate a large normal force between rollers 40 and hub surface 32a and between rollers 40 and pocket surfaces 38a and thereby, by virtue of the friction between rollers 40 and hub 32 .and between rollers 40 and ring gear 36, generate large axial forces resisting axial movement of rollers 40 on hub 32 and axial movement of ring gear 36 on rollers 40. Spring member 58 need only be strong enough to maintain ring gear 36 in its leftward or rearward position when the engine is not being cranked.

It will of course be understood that the use of a spring at one face of ring gear 36 eliminates the need to maintain a controlled spacing or tolerance between confronting faces 36a and 48d, thereby effecting a savings in both tooling cost and assembly time.

During operation of the engine, lubricating oil supplied in known manner to timing chain 46 drips off of that chain and is caught in trough 44f; the lubricant thus collected in trough 44f Hows down the trough and through an opening 44L in casing wall 44h, whereafter it ows circumferentially around ring gear 36 to the lower peripheral portion of that gear where it is deposited in a trough 76 formed between the lower portion of casing 44 and the lower portion of cover 48. The lubricant deposited in trough 76 builds up within the trough to the level of lip 44L on casing 44, whereafter the lubricant overflows lip 44L to maintain the lubricant level at the 75 level of the lip, The lubricant within trough 76 functions to lubricate the geared connection between pinion 66 and ring gear 36; it also serves to lubricate the rolling engagement of rollers 40 on hub 32 and ring gear 36; it further functions during overrunning action of hub 32 within ring gear 36 to lubricate the running surfaces between hub 32 and ring gear journal portions 36a.

While a preferred embodiment of the invention has been illustrated and described in detail it is to be understood that various changes may be made in the disclosed embodiment without departing from the scope or spirit of the invention as defined by the appended claims.

We claim:

1'. In a motor vehicle of the type including an engine having a block and a crankshaft journaled in said block and projecting at the rear of the block for connection to a transmission; a starter and timing mechanism comprislng:

(A) a ring gear mounted forwardly of said block on a forward extension of said crankshaft;

(B) an overrunning clutch interconnecting said ring gear and said crankshaft extension;

(C) a timing sprocket mounted on said crankshaft extension between said ring gear and said block;

(D) a timing chain engaging said timing sprocket and extending upwardly therefrom adjacent the forward face of said block for coaction with another timing sprocket on the engine camshaft;

(E) a housing fixedly secured to the forward face of said block and including a lower portion fitted over said crankshaft extension and encasing said ring gear, clutch, and timing sprocket and an upper portion encasing said timing chain;

(F) an electric motor fixedly secured to said housing lower portion; and

(G) a pinion gear on the output shaft of said motor held in constant meshing engagement with said ring gear and operative to drive the latter and thereby said crankshaft in response to energization of said motor.

2. A motor vehicle according to claim 1 wherein:

(E) said ring gear and said pinion gear are both of the screw type with the axis of said motor output shaft arranged substantially at right angles t0 the axis of said crankshaft.

3. A motor vehicle according to claim 1:

(H) Iwherein said overrunning clutch comprises (l) a hub on said crankshaft extension passing at its forward end through a central aperture in said lower housing portion;

(2) a plurality of pockets defined by cutouts at the inner periphery of said ring gear; and

(3) a roller in each of said pockets rollably engaging the outer periphery of said hub and the radially outer wall of said pocket; and

(I) said motor vehicle further includes a pulley secured to the forward face of said hub for driving connection to one or more accessory drive belts.

4, A motor vehicle according to claim 3` wherein:

(G) said pulley includes a hub portion rearwardly of the sheave portion thereof; and

(H) an inertia ring is carried on said hub portion to provide a vibration damper for said engine.

5. A starter mechanism for a motor vehicle engine of the type including a crankshaft comprising:

(A) a ring gear of the screw type mounted on said crankshaft with the gear teeth cut into one side face of said ring gear;

(B) an overrunning clutch interconnecting said ring gear and said crankshaft and comprising (l) a hub on said crankshaft;

(2) a plurality of pockets defined by cutouts at the inner periphery of said ring gear; and

(3) a. roller in each of said pockets rollably engaging the outer periphery of said hub and the radially outer wall of said pocket;

(C) an electric motor arranged with the axis of its output shaft substantially at right angles to the axis of said crankshaft;

(D) a pinion gear of the screw type on the output shaft of said motor positioned at said one side of said ring gear and held in constant meshing engagement with the latter;

(E) a casing defining (l) an anular bearing surface at said one side of said ring gear against which a bearing surface defined on said one side of said ring gear is positioned; and

(2) a reaction surface at the other side of said ring gear; and

(F) a spring member positioned between said reaction surface and said other side of said ring gear biasing said ring gear against said annular bearing surface.

6. In a motor vehicle of the type including an engine having a block and a crankshaft journalled in said block and projecting at the rear of the block for connection to a transmission; a starter and timing mechanism comprising:

(A) a ring gear mounted forwardly of said block on a forward extension of said crankshaft;

(B) a timing sprocket driving a timing chain mounted on said crankshaft extension between the forward end of said block and said ring gear;

(C) an overrunning clutch interconnecting said ring gear and said crankshaft extension;

(D) an electric motor;

(E) a pinion gear on the output shaft of said motor held in constant meshing engagement -with said ring gear;

(F) a casing enclosing said ring gear and said clutch and defining a trough positioned around the lower peripheral portion of said ring gear; and

(G) means operative to collect the lubricant dripping from said timing chain and route it to said trough whereby to lubricate the driving connection between said ring gear and said pinion gear.

7. A motor vehicle according to claim 6 wherein said trough extends upwardly to at least the level of the lower peripheral portion of the driving connection between said ring gear and said overrunning clutch, whereby the oil collected in said trough also serves to lubricate the driving connection between said ring gear and said overrunning clutch.

References Cited UNITED STATES PATENTS 20 2,731,005 1/1956 Lausen 12S-179 2,908,353 10/1959 Issacs et al. 123--179 3,108,490 10/1963 Turlay '74-574 FOREIGN PATENTS 186,912 9/1956 Austria.

WENDELL E. BURNS, Primary Examiner.

U.S. C1. X.R. 

